1. Field of the Invention
The present invention relates to a prosthesis suspension sleeve for use in attaching a below the knee prosthesis to the remaining portion of the patient's limb and more particularly pertains to a flexible, non-compressive urethane sleeve having integrally formed reinforced portions which provide for varying degrees of axial and circumferential stretching. The reinforced portions provide mechanical strength and resistance to tearing.
2. Description of the Prior Art
The general problem of attaching or suspending a below knee prosthesis to the remaining portion of a patient's limb has been addressed in the prior art. Various means and apparatus have been developed with the goal of providing a secure attachment that provides the amputee the ability to conduct his affairs without fear of losing his prosthesis during normal or strenuous activities. Mechanical means such as suspension belts and thigh lacers suffer from the disadvantage of being compressive about the thigh and of constricting the blood circulation in the thigh. Additionally, these devices do not solve the problem of pistoning, wherein the residual limb moves within the socket of the prosthesis in response to forces exerted upon the prosthesis. Pistoning further promotes tissue and skin problems including but not limited to irritation, lesions, and abundant perspiration.
In an attempt to solve these problems, sleeves made of elastic materials were developed. One such sleeve is disclosed in U.S. Pat. No. 5,593,454 to Helmy which discloses a sleeve having a reinforcing web formed throughout the sleeve. The web may be formed in either of two different weave patterns for controlling the stretch parameters of the sleeve. The sleeve itself has a barrel shape which provides smaller openings at the ends of the sleeve than would a cylinder.
A reinforced elastic sleeve is also disclosed in U.S. Pat. No. 4,822,371 to Jolly et al. This sleeve includes an internal cylindrical like panel which has a fabric surface with a low coefficient of friction. It is claimed that the panel serves to decrease irritation to the wearer and to improve the durability of the sleeve.
Another example of a prosthesis sleeve is disclosed in U.S. Pat. No. 4,479,272 to Beldzisky. A retaining sheath is disclosed which is open at both ends and includes an upper elastic retention portion, a lower elastic retention portion, and an intermediate articulation portion. The two end portions are axially non-stretchable, but are radially elastically stretchable. The middle portion is stretchable both axially and circumferentially.
In U.S. Pat. No. 5,769,809 a limb protector apparatus is disclosed which provides for progressively variable capacity for resilient stretching along the length of a tubular member.
All of the above-identified apparatus provide for attachment of the prosthesis to the limb by means of compression or constriction of the thigh. As is well known, many amputees have circulatory problems which are exacerbated by the apparatus of the prior art. A tourniquet effect restricts the flow of blood in the residual member, leading to discomfort and other complications.
Another method of suspending or attaching a below knee prosthesis is disclosed in U.S. Pat. No. 4,923,474 to Klasson et al. A sleeve member having a frusto-conical shape with a truncated end encloses an amputation stump. A coupling means is formed at the distal end of the sleeve for attachment to a prosthesis or other appliance.
While this type of apparatus provides for suitable adhesion of the inside of the socket liner to the skin of the stump, forces acting upon the distal coupling means cause stretching of the skin. This stretching of the skin promotes the aforementioned skin and tissue problems associated with pistoning.
It would therefore be desirable to provide a durable prosthesis suspension sleeve for use in attaching a below the knee prosthesis to the remaining portion of the patient's limb which can be used either alone or in combination with a sleeve attachable to a prosthesis and that eliminates the problem of pistoning and which non-compressively adheres to the prosthesis and to the limb.